1. Field of the Invention
The present invention relates to a bipolar battery, an assembled battery, a combination assembled battery, and a vehicle using the assembled battery or the combination assembled battery.
2. Description of the Related Art
In recent years, as electric vehicles have been developed more actively, secondary batteries have also been developed more actively. Among the secondary batteries, a lithium ion battery is particularly a high-performance battery characterized by compactness, lightweight, high energy density, high power density, and the like, and accordingly, has gained attention as a battery mountable on such an electric vehicle.
However, in order to apply the secondary battery to the vehicle, it is necessary to connect a plurality of the secondary batteries in series for the purpose of ensuring large power. However, when the batteries are connected to one another through connecting portions, the power of the connected batteries is lowered due to electric resistance of the connecting portions, and a disadvantage occurs also in terms of a space.
As a battery which solves the problems described above, there has been developed a bipolar battery composed by including bipolar electrodes in each of which a positive electrode and a negative electrode are individually formed on both surfaces of a collector (refer to Japanese Patent Application Laid-Open Nos. 2000-100471 and 2000-195495).